Rig mat sprayed with polyurea systems

ABSTRACT

A containment mat generally including matting tiles and a polyuria/polyurethane coating. Matting tiles are preferably formed from composite recycled rubber and are arranged in a first layer and a second layer with overlapping edges forming a shiplap design. The polyuria/polyurethane coating is sprayed on the seams between matting tiles creating a solid containment mat. A rig mat system may include a rig mat and a sealed leak-proof containment berm made from geo-fabric and foam blocks that are encapsulated in the geo-fabric and sprayed with the polyuria/polyurethane coating. The area between the berm and the matting tiles creates a trough for containing liquids.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit under 35 U.S.C. §119(e) of the earlier filing date of U.S. Provisional Patent Application No. 61/755,591 filed on Jan. 23, 2013, which is hereby incorporated by reference.

FIELD OF THE INVENTION

This application discloses an invention which is related, generally and in various embodiments, to solid containment for the oil and gas industry and other areas.

BACKGROUND OF THE INVENTION

Fracking is a method of extracting natural gas that is trapped in layers of shale beneath the Earth's surface. The process involves drilling into the shale layers and pumping pressurized fluid to recover natural gas. The environment is exposed to harmful contaminates during the drilling and recovery process of natural gas and oil products.

Typical drilling sites are constructed and developed with heavy earth moving machinery until the best substructure is created to stabilize the ground that the drilling rig is placed on. A textile such as a geo-fabric is placed down after gravel has been circulated throughout the drilling pad. HDPE plastic liner (30 to 60 mil) is then laid down over the textile, which it is seamed together by a weld. HDPE is designed to capture and contain any spillage on the drilling site. At the end of the HDPE liner usage it is transported for disposal to a landfill.

Rig mats are placed on top of the HDPE liner, the rig mats provide a flat surface that allows the equipment to operate on a durable surface. The rig mats also offer solid flooring for mud pumps, pipe racks, drill pipe, shakers, heavy equipment and the drilling rig. The existing drilling mats that are most typically used are made of wood that interlock inside of a steel bracing. These wooden mats absorb the oil base material that comes about during drilling that cannot be removed. These wooden mats weigh on average 3500-4500 lbs. The weight of these current mats threatens the integrity of the plastic liner during the installation process. Also, HDPE systems are often breached when heavy equipment is tracked over the HDPE plastic liner. Typical HDPE plastic liners are replaced three times per well due to the amount of breaches created. In addition to drilling sites, there is also a need for containment mats in other areas such as farming.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the invention are described herein in by way of example in conjunction with the following figures, wherein like reference characters designate the same or similar elements.

FIG. 1 shows a perspective view of upper and lower matting tiles according to embodiments of the invention.

FIG. 2 shows an end view of the upper and lower matting tiles of FIG. 1.

FIG. 3 shows a top view of the upper and lower matting tiles of FIG. 1.

FIG. 4 shows an end view of two sets of the upper and lower matting tiles of FIG. 1.

FIG. 5 shows a top view of a containment mat system including a containment mat and a containment berm according to embodiments of the invention.

FIG. 6 shows a partial side view of the containment mat system of FIG. 5.

DETAILED DESCRIPTION

It is to be understood that at least some of the figures and descriptions of the invention have been simplified to illustrate elements that are relevant for a clear understanding of the invention, while eliminating, for purposes of clarity, other elements that those of ordinary skill in the art will appreciate may also comprise a portion of the invention. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the invention, a description of such elements is not provided herein.

The Figures illustrate various embodiments of a system for a rig mat sprayed with polyuria system; common parts will be represented by the same reference numeral. The rig mat according to embodiments of the invention creates a flooring for the drilling rig and is a non-breachable sealed system for containing liquids that may be harmful to the environment produced by the drilling and hydraulic fracking process.

The rig mat of various embodiments is indicated generally by reference number 10. The rig mat 10 generally includes two major components: matting tiles 12 and a polyurea coating 14. Matting tiles 12 are preferably formed from composite recycled rubber and are arranged in a first layer 16 and a second layer 18 with overlapping edges forming a shiplap design. Each of the matting tiles 12 preferably has a diamond plated surface. The polyurea coating 14 may be a suitable polyurea coating or, alternatively, a polyurethane coating. The polyurea coating 14 is sprayed on the seams between matting tiles 12 creating a solid containment mat 10. The rig mats are rated to withstand 2000 psi and the polyurea coating has a psi rating of 2000 to 3500 psi. The rig mats are preferably made from recycled rubber tires and do not absorb oil based drilling mud and condensates like a wooden rig mat.

The containment mat system, in one embodiment, includes a containment mat 10 and a sealed leak-proof containment berm 20 extending, for example, 5 feet outside the perimeter of a, for example, 60,000 to 90,000 square foot drilling pad. The containment berm 20 comprises containment barriers 24 that are encapsulated in geo-fabric 22 and sprayed with the polyurea coating. The containment barriers 24 in this embodiment are, for example, foam blocks. Geo-fabric 22 extends from the matting tiles 12 to containment berm 20 forming a trough 26 for containing liquids. The geo-fabric 22 is preferably a heat-treated felt. In another embodiment for farm tank containment, the mat size is smaller ranging from 3000 to 4000 square feet and the containment barriers 24 are modular barriers such as jersey barriers.

The method of making the rig mat system including a rig mat 10 and containment berm 20 according to embodiments of the invention includes arranging the first layer 16 and a second layer 18 of matting tiles 12 with overlapping edges in both longitudinal and transverse directions such that each of the seams in the first layer is offset with relation to each of the seams in the second layer, thus, forming a shiplap design. In one embodiment, each matting tile 12 is 14 feet by 7.5 feet by 2 inches and the edges are overlapped 3 feet in each direction. The number of mats per site may range from 571 to 857 mats depending on the square footage of the site which is typically 60,000 to 90,000 square feet. Seams between matting tiles 12 are sprayed with the polyuria coating 14 with a travel path of 6 to 8 inches after each layer 16, 18 is formed. Wrapping a foam block 24, for example, 8 inch by 8 inch, with geo-fabric 22 and sealing with the polyuria coating to protect and create the sealed leak proof containment berm 20. The berm 20 and geo-fabric 22 is which is sprayed 30 to 60 mils with the polyuria coating 14. The berm 20 and geo-fabric 22 is placed around all 4 sides of the rig mat 10 such that there is 5 feet between the containment berm 20 and the rig mat 10 and the geo-fabric 22 lays under the edge of the rig mat 1 to 2 feet. Additional polyuria coating 14 is sprayed in the corners 28 of the trough 26 formed between the containment berm 20 and the rig mat 10.

The containment or rig mat of various embodiments has increased strength withstanding extreme pressures and has a higher resistance to the hydraulic fracturing acids and chemicals than traditional lining systems. The rig mat does not have to be replaced like a typical rig mat and can be reused at a different well, thus, lessening the process schedule. The shiplap design of various embodiments of the invention creates an interlocking system that allows all of the matting tiles 12 to be interlocked to each other without gaps between the matting tiles 12. The rig mat of various embodiments also could be used in other industries such as power plants or construction, and could also be used as a temporary roadway for heavy equipment hauling and machinery moving in isolated areas when paths are obstructed by snow and/or mud. The rig mat could also be used in applications when shock resistance and electrical current are involved.

Nothing in the above description is meant to limit the invention to any specific materials, geometry, or orientation of elements. Many part/orientation substitutions are contemplated within the scope of the invention and will be apparent to those skilled in the art. The embodiments described herein were presented by way of example only and should not be used to limit the scope of the invention.

Although the invention has been described in terms of particular embodiments in this application, one of ordinary skill in the art, in light of the teachings herein, can generate additional embodiments and modifications without departing from the spirit of, or exceeding the scope of, the claimed invention. Accordingly, it is understood that the drawings and the descriptions herein are proffered only to facilitate comprehension of the invention and should not be construed to limit the scope thereof. 

What is claimed is:
 1. A containment mat comprising: a first layer of matting tiles wherein first seams are formed between adjacent matting tiles in the first layer; a second layer of matting tiles wherein second seams are formed between adjacent matting tiles in the second layer, wherein the second layer is disposed on top of the first layer such that matting tiles in the second layer overlap matting tiles in the first layer in both longitudinal and transverse directions and each of the first seams is offset with relation to a second seam; and a coating disposed in the first and second seams, wherein the coating is selected from the group consisting of polyureas and polyurethanes.
 2. The containment mat of claim 1, wherein the matting tiles comprise rubber.
 3. The containment mat of claim 1, wherein the rubber is composite recycled rubber.
 4. The containment mat of claim 1, wherein the first layer and second layer form a shiplap design.
 5. A containment mat system comprising: a containment mat comprising: a first layer of matting tiles wherein first seams are formed between adjacent matting tiles in the first layer; a second layer of matting tiles wherein second seams are formed between adjacent matting tiles in the second layer, wherein the second layer is disposed on top of the first layer such that matting tiles in the second layer overlap matting tiles in the first layer in both longitudinal and transverse directions and each of the first seams is offset with relation to a second seam; a coating disposed in the first and second seams a coating disposed in the first and second seams, wherein the coating is selected from the group consisting of polyureas and polyurethanes; and a containment berm spaced from and surrounding the perimeter of the mat; and a containment trough disposed between the containment mat and the containment berm.
 6. The containment mat system of claim 5, wherein the trough comprises fabric disposed between containment mat and the containment berm.
 7. The containment mat system of claim 6, wherein the fabric is the geotextile fabric.
 8. The containment mat system of claim 7, wherein at least a portion of the containment berm is covered in geotextile fabric.
 9. The containment mat system of claim 8, further comprising a coating disposed on the geotextile fabric comprising the trough and covering the containment berm, wherein the coating is selected from the group consisting of polyureas and polyurethanes.
 10. The containment mat system of claim 5, wherein the matting tiles comprise rubber.
 11. The containment mat system of claim 10, wherein the rubber is composite recycled rubber. 